Does the crash happen to all files, old and new or just new ones?
I would also check the files for integrity. and if that also fails, check the data storage.
Does this happen on a local drive or some kind of network device?

The smallest check you can do right now: check the mass data storages first
Either with an elevated command shell (with administrator access rights) and the command:
chkdsk c: /v /f
(repeat this command for each drive letter of non-read-only devices)
If the program asks you whether you would like to plan a check because the drive is currently in use, respond with "yes". Then reboot your system.

When i select the string of leters abd click right button of mouse - app crashes.
There is no button for reply...
It crashes when I use content menu. It means when I use right click...
I do not know how to replay 'cause where is no "replay" button...
Integrity of all discs is ok. Version of mp3.tag is 2.90a. Using Win 10 Home version 18.03 build 17134.407
sfc did not find any violation of system files.

And did it help in some way?
I also supplied another link.
But perhaps it may be less time consuming to get a description of what you did.
What do you mean by "(copy - paste)"? Usually you open files for MP3tag with drag & drop.
Copying and pasting will only work on a per-field basis or if you have copied the whole tag and want to paste that.
What does the crash look like?